All items in the game have a base value, which is multiplied by what material the item is made of and by the item's quality. Decorations (such as bone, gems, and studding) further increase the value.

Item quality can have an effect on an item's properties, especially armor and weapons.

Rooms also have a "quality grade" which determines their value in the eyes of those owning/using the room, which is the sum of the objects placed within their designated area plus the materials that surround it plus improvements (such as engraving) to those materials. See room for a more complete discussion of these values, and How do I increase the value of a room for a complete list of options.

Contents

All crafted items (furniture, armor, bolts, etc.) – but not intermediate materials (bars, blocks, etc. except cloth, which does have quality levels) – are bracketed by characters that show the quality of their craftsdwarfship. Dyeing also has a quality level, as does decorating (with gems, leathers, cloth, etc). Prepared foods have quality levels, but simple foods and drinks do not.

A masterpiece is more than the highest normal quality and value - it is an artistic expression that is of great importance to the dwarf who created it.

When a masterful quality item is created, the game will announce, "<dwarf> has created a masterpiece!" The loss, destruction or theft of such a masterpiece will cause the dwarf that created it a very unhappy thought. Trading a masterpiece item to merchants is always safe. Masterpiece meals can be eaten safely, although allowing the food to rot will provoke the same response as theft or destruction. Using masterpiece bolts will not cause a tantrum, even if the bolts break - however, losing a bolt, even one left on the battlefield, will. So if a kobold or wild animal steals a used masterpiece bolt which was lying around, or misses its target and falls into the chasm or is melted by "the impertinent magma", this also counts as defacement, and the maker's mood will decrease drastically.

Since legendary dwarves are most likely to be the ones creating masterpieces, keeping these creations safe should be high priority; tantruming legendary dwarves can be very difficult to subdue (as was discovered the hard way in Boatmurdered).

Artifact items have a unique name instead of bracketing symbols and are worth 120x base value. Unlike masterpiece items, losing an artifact will not result in unhappiness unless the current owner is obsessed with it - in this case, losing the artifact will cause said dwarf to go insane. According to inspections of the memory values, it seems that artifacts have the same quality value as masterpiece items. It is unclear if this is true for weapons/armor or not - opinions differ as to whether artifact weapons and armor have a 2.0 multiplier or something higher; nothing has been found in the game code to support such, but observation suggests otherwise.

Tradesdwarves of higher skill levels will tend to produce items of higher quality. Looking at the table below, we see that "Dabbling" dwarves never (without an applicable preference) produce anything above a basic "no quality" item, Proficient dwarves (the highest possible skill level at embark) always produce at least some quality and usually +Finely Crafted items+, while legendary dwarves usually (65% of the time) produce ≡Exceptional items≡, and the best legendary dwarves produce nothing less than ≡Exceptional≡ and produce ☼Masterful items☼ approximately 27% of the time.

The in-game calculations to determine final quality of a product work like this: first, a skill level is computed, directly related to the dabbling through legendary+5 indicators and preferences of the particular crafter. "No skill" or dabbling is 0, proficient is 5, legendary is 15, etc. Skill levels are capped at 20, then item/material preference bonuses are added (so Legendary +5 will produce Masterpieces more often in their preferences).

Item quality is set to 0.

Then dice are rolled. Each roll is independent; all rolls are made even if a previous roll fails.

If d5 < skill level, quality of final product is bumped.

If d10 < skill level, quality is bumped.

If d15 < skill level, quality is bumped.

If d20 < skill level, quality is bumped.

If d25 < skill level and d3 == 1, quality is bumped.

This gives the 6 quality levels (0 to 5).

According to inspections of the memory values, it seems that artifacts have a quality of 5.

Most obviously, quality influences the monetary worth of an object, for purposes of trading and determining price (the latter once economy starts). Destruction of a masterwork will also cause relevant unhappiness. However, for some items, quality may also influence other things.

The quality of any weapon, including crossbows used as launchers, affects the skill of the shooter. I think this even leads to obscene things like master crossbows + master bolts causing recruits to shoot like legends. In general, if the quality Q is from 0 to 5, the skill is modified according to

Skillnew = Skilloriginal × (1.0 + 0.2 × Q) + Q

This is pretty extreme and will probably be reduced for all weapons.

See this chart for the exact levels:

Note: This chart is out of date/wrong due to the facts that the integer that represents a specific skill level is not known, how the formula rounds is not known, and the fact that higher legendaries exist is known.

Result for

Well-crafted

Finely-crafted

Superior quality

Exceptional

Masterful

Dabbling

Novice

No-label

Competent

Skilled

Proficient

Novice

No label

Competent

Skilled

Proficient

Adept

No label

Competent

Skilled

Talented

Adept

Professional

Competent

Skilled

Talented

Adept

Professional

Great

Skilled

Proficient

Adept

Professional

Great

High Master

Proficient

Adept

Professional

Great

High Master

Legendary

Talented

Expert

Accomplished

Master

Grand Master

Legendary

Adept

Professional

Great

Grand Master

Legendary

Legendary

Expert

Accomplished

High Master

Legendary

Legendary

Legendary

Professional

Great

Grand Master

Legendary

Legendary

Legendary

Accomplished

High Master

Legendary

Legendary

Legendary

Legendary

Great

Grand Master

Legendary

Legendary

Legendary

Legendary

Master+

Legendary

Legendary

Legendary

Legendary

Legendary

If this is true, then it would be possible to:

Train a couple dozen skilled miners

Give them exceptional picks

Draft them and give them decent armor

Kill a goblin siege with a couple dozen legendary speardwarves (picks = 70% damage spears) as long as there are no enemy champions to destroy your armour/shield/wrestling inept speardwarves